CMOS driver circuit
US5015880A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1989 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | Oct 10, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/01721
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A CMOS integrated circuit for driving capacitance devices is provided. The circuit has an input node and an output node and includes a first transistor operatively connected to the input node which is turned "on" and "off" by the input node to supply an output signal to the output node when turned "on". A second transistor is provided, the output of which is connected to the output node when turned "on" to supply an output signal thereto. A control circuit is provided to turn on the first transistor prior to the second transistor, and to turn on the second transistor if and only if the slew rate of the output signal of the first transistor is less or slower than a given value. With this arrangement, if there is a low total capacitance of the capacitance devices being driven, the first transistor will have a fast enough slew rate that it will perform the entire charging function of the devices without turning on the second transistor; however, if the total capacitance of the devices being charged is sufficiently large, the low slew rate of the first transistor will cause the second transistor to be turned on, thereby providing additional charging voltage to the capacitance devices, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.